JPS607774B2 - Manufacturing method of dry transfer material - Google Patents

Description

[Detailed description of the invention] The present invention relates to the production of dry transfer materials.

Conventionally, transfer materials have been made by printing the figure to be transferred onto a base plate, and this figure is then peeled off, for example, by the action of an overcoat or an overprint adhesive.

The production of transfer materials of this type therefore requires the use of printing machines and the production of suitable printing plates, cylinders, screens and the like. Since the implementation of this method requires a large investment of money and consumption of time, in recent years a number of proposals have been made for the production of transfer materials, some of which include imagewise exposure of a photographically sensitive material. , which involved developing the exposed material to form an adhesive transferable image on the base sheet. Examples of this type of method include British Patent Specification No. 1079661;
There are those described in No. 129196 and No. 1364627. The photographic method has the advantage of being able to produce sheets according to orders in a short period of time, and theoretically can be produced while customers are waiting at the store.
Although it is relatively easy to produce image indicia by photographic methods, in order for the image indicia thus produced to be transferable to the receiving surface, that surface must have adhesive properties. There is a need.

For example British Patent Specification Nos. 1079661 and 13
In the method described in No. 64,627, after exposing and developing the image indicia, a layer of pressure sensitive adhesive is added. However, this method requires the final processing step of applying a layer of adhesive in a relatively slow process, processing each piece individually, when the customer is holding the order. It has the disadvantage that it is not possible to use the desirable method of layering at a time when a coating device using a relatively high-speed continuous sheet feeding can be used at the initial manufacturing stage where there is no urgency to complete the product production within a short time. . This method further provides that when transferring the image indicia, the pressure of the stylus applied outside the image area causes the adhesive to be partially transferred, creating smudges on the transparent receiving surface and also on other surfaces. It has the disadvantage of adsorbing dust and dirt. Another method is described in British Patent Specification No. 129196, in which an adhesive is coated as an intermediate layer in a three-layer system, and the developed image is deposited between the adhesive layer and the underlying pigment layer. Use as a mask for polish removal with solvents,
Finally, the developed image is removed to expose the adhesive-covered image indicia. However, this method first requires three layers of coating instead of two, and second requires an extra step for using different types of solvents to process the different types of layers; Third, the process of cutting out the image using a solvent is very delicate, making it difficult to maintain a constant quality of the product. Yet another method is to add a fusible component to the photosensitive polymer layer itself so that it is tacky enough to transfer the developed image to the receiving surface.

However, this size requires processing to prevent the transferred image from becoming sticky. In this way, the tacky photosensitive layer can be coated onto an tacky release layer, and the latter can be coated onto the base layer. When this transfer material is transferred, the release layer is cut deep and transferred together with the image, and the surface becomes non-tacky. However, this method also has the disadvantage that even outside the image area, the release layer is transferred to areas exposed to the pressure of the stylus, resulting in smudges on a transparent receiving surface. Another method for ensuring that the adhesive-coated surface after transfer does not have tackiness and does not leave any blemishes in areas outside the image is to use a first layer that does not contain an adhesive component and a second layer that includes an adhesive component. Some use two photosensitive polymer layers stacked one on top of the other. When this transfer material is exposed and developed, an image is obtained in which the surface on the base layer side has no tackiness and the surface on the opposite side has tackiness. However, in this method, firstly, if the same exposure method is used for both layers as is desirable, since both layers use the same solvent, the first layer will be adversely affected by the coating of the second layer and will not exhibit uniform properties. First, it has the disadvantage that it is difficult to have a high degree of control over the adhesion of the second layer while maintaining sufficient photosensitivity and developability. Other disadvantages of conventional photographic transfer material manufacturing methods include insufficient image opacity, especially in the case of black characters. This is because any pigments included in the layer absorb or reflect the chemically active radiation used to produce image-dependent changes in the coating components to the same extent as they absorb or reflect light in the visible range. It is. The pigment thus prevents the chemically active radiation from reaching areas remote from the surface on which the image rays are projected. In these methods, the same situation occurs even in the absence of pigments, unless the sensitizer that absorbs chemically active radiation during irradiation decomposes itself into a type that does not absorb chemically active radiation. That is, the sensitizer near the surface where the chemically active radiation is incident will continue to absorb the chemically active radiation even after the desired image shape change has occurred in the coating component, penetrating deeper into the layer. Preventing necessary changes from occurring in this area. The characteristics of these systems are shown in FIG. 1 by curve A, which shows the light density versus the logarithmic scale of exposure. The optical density (or density) of the developed image increases only slowly with the logarithm of exposure. For example, in the case of 3.6-4.0), a 29 sand exposure at a distance of one skin from a 2 kW Adlux mercury metal halogen lamp will generally result in an optical density of 1.0 after development. Similarly, the thickness of the coating layer is 15-20
The thickness of the image area after exposure and development is approximately 5 microns. Increasing the exposure will increase the opacity and thickness of the image to some extent, but in the example above, to obtain an optical density of 3 the exposure would be 200 sand, and for an optical density of 4 the exposure would be 2000 sand.
It is necessary to extend it to 0 seconds. Such exposure is not only practically impossible, but also causes unnecessary opacity in areas other than the image area due to scattered light. According to the present invention, the base layer is made of a homopolymer or copolymer of polyvinyl alcohol and vinyl acetate imparted with photosensitivity, is insoluble in water but swellable with water, and is formed on a transparent or translucent base layer. applying a first layer whose adhesion to the adhesive increases upon exposure to light; over this first layer a second layer of an adhesive material that permits water penetration but is not soluble in water; The composite material produced is imagewise exposed to enhance the adhesion of the first layer to the base layer in the exposed areas; and the so exposed material is developed with water to improve the adhesion of the first layer to the base layer in the unexposed areas. 1st
and completely removing the second layer.

In the method of the present invention, a short exposure produces a clear, highly opaque, adhesive-coated image indicia within the exposed image area and having substantially the same thickness as the initial composite material. can be made. Furthermore, the image has excellent and moderate tack, and the non-image areas are free from any contamination by adhesive or release layer, and can be easily transferred to a receiving surface. Furthermore, the method requires only one post-exposure processing step of the image. In addition, in this method, the adhesion to the base layer can be changed by only slightly changing the composition of the components. Layers can be used but are rarely needed. By this method, the resulting image markings formed in the exposed image areas of the transfer material and coated with adhesive can be transferred from the substrate to the receiving surface by means of the adhesive coating. Furthermore, techniques for achieving complete release from the base layer as described in GB 95967 can also be used. The second (adhesive) layer is permeable to, but must be insoluble in, the solvent used to develop the image.

This condition is achieved by making the second (adhesive) layer suitably rupturable. That is, this is achieved by making the adhesive so low that it can be easily cut. Naturally, in this method, after exposure and development, there is no adhesive on the base layer in the blank area between the image indicia, and therefore only one exposure of the image to the photosensitive material is required. Processing automatically yields a ready-to-use dry transfer material.
In order to easily produce the materials used to carry out the transfer according to the method, the first (photosensitive) layer is coated with a water-based solution or dispersion and the second layer is coated with an adhesive. It is desirable that the layer is formed by a solution or dispersion using a method or compounding material that does not adversely affect the first layer, such as using an organic solvent that is immiscible with water.

The adhesive used to create the second layer can be a pressure-sensitive adhesive, such as polyvinyl ethyl ether, polyvinyl isobutyl ether, polyisobutylene, various acrylic acid ester polymers, tackified rubber, ethylene pinylacetate, etc. It can be formulated from a wide range of materials available as These can be tempered by the use of resins, especially silicic acid, which has properties that improve water permeability. Other materials that improve water permeability can be added, such as wetting agents such as polyvinyl methyl ether or water-soluble resins. The first (photosensitive) layer is insoluble but swellable in the solvent used to develop the image, and its adhesion to the base layer increases upon exposure to light.

The use of this material allows the image areas after development to retain almost their full original thickness and therefore their opacity, while in the areas outside the image, the developer dissolves the coating layer, reducing both the thickness and opacity. Becomes zero. Although the mechanism has not yet been completely elucidated, actual measurements have shown that the adhesion between the first layer and the base layer is strengthened by exposure to light, and a photoadhesion phenomenon is clearly observed. Additionally, exposure changes the contact angle of the surface adjacent to the base layer, resulting in a difference in the resistance to water ingress at the interface between the base layer and the photosensitive layer during the development process. When the transfer material of the present invention is used, the optical density, or density, increases very rapidly within the narrow exposure range, as shown by curve B in FIG.

A transfer material with a characteristic curve of this type also has the important advantage that weak exposures, e.g. by scattered light, do not result in any opacity at all, unless the exposure is close to the degree of exposure required for the film to remain completely thick. have. Therefore, a clear image with high opacity can be obtained. The most convenient developer to use is water. Therefore, the first photosensitive layer must be water-insoluble but swellable. Polyvinyl alcohol noacetate photosensitized with a diazo resin is suitable as a photosensitive material system. However, when used as a stencil material, it is not water-soluble before exposure to light, but by increasing the component ratio of polyvinyl acetate or its copolymer to polyvinyl alcohol, it is already water-resistant before exposure to light. gender. It has been discovered that this unexposed material can unexpectedly be washed off the substrate by water, whereas the exposed material remains strongly attached to the substrate. The ratio of alcohol to acetate copolymer is determined by the exact chemical formula of the alcohol and copolymer used. In practice, when using a series of formulations with various acetate polymer to alcohol ratios, those with high alcohol content have properties similar to curve A in Figure 1, and the acetate copolymer Items with a large content tend to have characteristics similar to curve B. Intermediate transitional characteristics show an image in which the thickness of the film remains completely in one part, but in another part the film is washed away and the thickness remains thinner and mottled, as expected from curve A. or by a closely spaced optical density-exposure logarithm curve, such as curve C in FIG. The advantages of the invention are fully realized only if the ratio of polyvinyl acetate to polyvinyl alcohol copolymer is sufficiently large to achieve properties of the type shown in curve B. Intermediate characteristics, such as that shown by curve C, only partially realize the advantages of the invention. Furthermore, all polyvinyl acetate copolymers do not necessarily have correct solubility characteristics similar to curve C even if the content ratio to polyvinyl alcohol is increased. By using a plasticizer, the strength and flexibility of the image and its releasability from the base layer can be changed.

Although conventional external plasticizers such as tributyl phosphate can be used as plasticizers, internal plasticizers in the form of polyvinyl acetate copolymers are more preferred. The image obtained by development can be rendered opaque, and can be colored black, white, or any other suitable color of the spectrum by mixing appropriate pigments or dyes.

The base layer used in the method can be a thin film of a variety of transparent or translucent plastic materials or a laminate surfaced with any of these plastic materials.

A release coating can be applied if desired, but this is not normally necessary. Examples that help explain the present invention are given below.

Example 1 A photopolymer material is made as follows. Mobiol is a trademark for a series of polyvinyl alcohols made by Harlow Chemical Company. Vulcan 3 Flatfy is a carbon black pigment manufactured by Cabot Carbon Company.

Emaltex 530 is a 52.5% solids-in-water dispersion of polyvinyl acetate or polyvinyl acetate vinyl ester of versatic acid supplied by Harlow Chemical Company. Mowilis DHL is a 50% solids dispersion of polyvinyl acetate homopolymer in water supplied by Harlow Chemical Company.

Pinamul 6525 is a copolymer of polyvinyl acetate or polyvinyl caprate in a 56% solids dispersion in water supplied by Vinyl Products.

ZAL diazoresin is a zinc chloride double salt of 4-diazodiphenylamine, formaldehyde and concentrate supplied by Associated Press Maltstars. Manufacturing method Mopiol 4-8830 evening is Balkan 3 Flatsfi and 2
Pole milled in the water on the 10th evening.

Once the dispersion showed 7 in the Hegman cage (approximately 20 hours later), the 45 yen of the dispersion was tied to Mobiol 4-88.
55 minutes of a 12.5% solution of After 15 minutes, the resulting dispersion is slowly added to a mixture of Emaltex VV53030%, Mooris DHL50%, Vinamiyur 652520%.

After the addition is complete, continue boiling for another 3 minutes. Next, 55% of ZAL diazoresin solution was added in water to make it photosensitive. The final dispersion was filtered through a 9$ mesh to remove solids. Store overnight before coating on high density untreated polyethylene (4000) with a 36 wire helical member (wire diameter 900 microns).

The paper is dried in a stream of air at room temperature. The adhesive is prepared with the following formulation. Aromasol day 170 Tapitucolite Q-125 50% Aromasol daily solution 320 Taproduct 9 lines 1 evening EHBC 570 evening ・E
HBM 160 evening aerosol
160 evening CAS20/2
2760 taaromazole is an aromatic solvent supplied by ICI.

Pitucolite Q-125 is a terbene resin supplied by Pennsylvania Industrial Chemical Company.

Product 963 is a wetting agent supplied by Henkel.

EHBC and EHBM are polyvinyl ethyl ethers supplied by Bakelite Xylonite.

Aerosol 300 is a silicic acid supplied by Degussa.

CAS 20 No. 2 is an aliphatic hydrocarbon supplied by Carl's Cavell Andreonard Company.

Erosol and Piccolite Q-125, Product 9
63 is mixed by hand and then EHBC and EHBM, Aerosol 300 are added using a stirrer. The mixture is passed through a Sanren loaf mill until homogeneous. CA
S20/2 solvent is added and mixed slowly, and all adhesive is thoroughly dispersed using a Silverson mixer.

Adhesive is No. 10 measur (wire diameter 25
0 micron) on the photopolymer layer and 3
Dry at 000.

The mixture thus obtained is exposed through a polyethylene support in contact with the negative with a water w Adalux lamp for 30 seconds at a distance of 100 skin.

The image is developed with a mist of cold water from the bathroom shower system to keep the image clean and clear on the support. Although the image appears to be adhesive on the surface, there is no adhesiveness at the locations of the support within the image. After drying, the paper was later removed with a stylus for preliminary peeling of the markings from the polyethylene carrier paper.
It can be rubbed. The adhesive then becomes powerful enough to pull the indicia released from the carrier paper and adhere to the desired receiving surface. Example 2 The base paper is a 75 micron polyester terephthalate film in 5% toluene.
% polyethylene wax (softening point 106 qo).

It is preferable that the coating weight is small. No. The 5-wire lathember produces the desired coating thickness. After removing the solvent with a gentle blow of air, the photosensitive layer is coated onto this at 25 DEG and dried in ambient air. Pigment distribution
(weight ratio) carbon black pigment
20 Mobiol 8.8812.5% solution
80 The above is run on a Sanren roll mill until the Hegman grind gauge reads 70.

Photosensitive layer (weight ratio) Pigment dispersion
10 Vinapas D500
50 Vina Pass 50/5VL
20ZAL 5% aqueous solution
10 Water 6 Next, to the dried photosensitive layer (weight ratio) Lutanol J60
1.0 Lutanol J30
6,5 Stabilite Estel 10
An adhesive layer consisting of 2.0 silicic acid 20 aliphatic hydrocarbon solvent 80.0 is applied.

Vinapass D5 Yui and Vinapass 50/L are polyvinyl acetate homopolymers and polyvinyl acetate copolymers supplied by Wacker Chemie.

Lutanol J60 and Lutanol J30 are polyvinyl isobutyl ethers supplied by Basf Corporation.

Stabilite Ester 10 is a hydrogenated rosin glycol ester supplied by Hercule.

The ingredients are stirred together using a strong stirrer using only half of the total solvent content, and the remainder is added little by little after the oxalic acid is completely dispersed. Coating and exposure details are similar to the adhesive part of Example 1. Example 3 Photosensitive paper was prepared in the same machine as Example 1 or Example 2 (weight ratio) Opanol B50 20% NV 12.5 (in aliphatic hydrocarbon) Opanol B3
6.0 Silicic acid 1.5 Oxitol 1.5 Aliphatic hydrocarbon
The adhesive is coated with a formulation of 68.0.

Opanol B50 and Opanol B3 are polyisobutylene resins supplied by Basf Corporation.

After drying the resulting mixture, it was exposed and developed in the same manner as in Example 1. Example 4 Photosensitive paper was prepared in the same manner as in Example 2, and Gelva RA788 17.0 (weight ratio)
It is coated with an adhesive layer consisting of Aerosol 300 3.0 White Spirit 80-0.

Gelva RA788 is a sticky acrylic polymer supplied by Monsanto.

Each component is vigorously rubbed until the silicic acid is dispersed.

The details of development and exposure are the same as in Example 1.

[Brief explanation of the drawing]

The drawing is an optical density logarithmic exposure curve diagram for explaining the present invention.

Claims (1)

[Scope of Claims] 1. A transparent or translucent base layer, which is made of a homopolymer or copolymer of polyvinyl alcohol and vinyl acetate imparted with photosensitivity, and is insoluble in water but swellable with water; applying a first layer whose adhesion to the adhesive increases upon exposure to light; over this first layer a second layer of an adhesive material that permits water penetration but is not soluble in water; The composite material produced is imagewise exposed to enhance the adhesion of the first layer to the base layer in the exposed areas; and the so exposed material is developed with water to improve the adhesion of the first layer to the base layer in the unexposed areas. A method for producing a dry transfer material, comprising: completely removing the first and second layers. 2. The first layer is formed using a water-based dispersion, and the second layer is formed using a solution or dispersion of an organic solvent that is immiscible with water. The method described in Scope No. 1. 3. The method according to claim 1 or 2, wherein the second layer is breakable. 4. The second layer is composed of polyvinylethyl ether, polyvinyl isobutyl ether, polyisobutylene, acrylic acid ester polymer, tackified rubber, or ethylene vinyl acetate adhesive. ~The method according to any one of Item 3. 5. The method according to any one of claims 1 to 4, wherein the first layer is made photosensitive with a diazo resin.